EC GATE 2010 (Test 2)



Tag: ec gate 2010
Q.1
The question below consists of a pair of related words followed by four pairs of words. Select the pair that best expresses the relation in the original pair. Unemployed: Worker
A. fallow : land
B. unaware: sleeper
C. wit : jester
D. renovated : house
Answer : Option B
Explaination / Solution:

A worker may by unemployed. Like in same relation a sleeper may be unaware.

Workspace
Report
Topic: Arithmetic Tag: EC GATE 2010
Q.2
If 137 + 276 = 435 how much is 731 + 672 ?
A. 534
B. 1403
C. 1623
D. 1513
Answer : Option C
Explaination / Solution:

Since 7 + 6 = 13 but unit digit is 5 so base may be 8 as 5 is the remainder when 13 is divided by 8. Let us check.
1378                                             7318
2768                                             6728
435                                   1632
Thus here base is 8. Now


Workspace
Report
Q.3
For the output F to be 1 in the logic circuit shown, the input combination should be

A. A = 1,B = 1,C = 0
B. A = 1,B = 0,C = 0
C. A = 0,B = 1,C = 0
D. A = 0,B = 0,C = 1
Answer : Option C
Explaination / Solution:



Workspace
Report
Q.4
The transfer characteristic for the precision rectifier circuit shown below is (assume ideal OP-AMP and practical diodes)

A.
B.
C.
D.
Answer : Option B
Explaination / Solution:




Workspace
Report
Q.5
The amplifier circuit shown below uses a silicon transistor. The capacitors Cc and CE can be assumed to be short at signal frequency and effect of output resistance r0 can be ignored. If CE is disconnected from the circuit, which one of the following statements is true

A. The input resistance Ri increases and magnitude of voltage gain Av decreases
B. The input resistance Ri decreases and magnitude of voltage gain Av increases
C. Both input resistance Ri and magnitude of voltage gain Av decreases
D. Both input resistance Ri and the magnitude of voltage gain Av increases
Answer : Option A
Explaination / Solution:

The equivalent circuit of given amplifier circuit (when CE is connected, RE is short-circuited)


Workspace
Report
Q.6
Suppose that the modulating signal is  and the carrier signal is , which one of the following is a conventional AM signal without over-modulation
A. x(t) = AC m(t) cos (2𝜋fC t)
B. x(t) = AC [1 + m(t)] cos (2𝜋fC t)
C. x(t) = AC cos (2𝜋fC t) +AC /4 m(t) cos (2𝜋fC t)
D. x(t) Acos (2𝜋fC tcos (2𝜋fm t)+Asin (2𝜋fm tsin (2𝜋fC t)
Answer : Option C
Explaination / Solution:
No Explaination.


Workspace
Report
Q.7
X(t) is a stationary process with the power spectral density Sx(f)>0, for all f . The process is passed through a system shown below

Let Sy (f ) be the power spectral density of Y(t). Which one of the following statements is correct
A. Sy (f ) > 0 for all f
B. Sy (f ) = 0 for |f| > 1 kHz
C. Sy (f ) = 0 for f = nf0, f0 = 2 kHz kHz, n any integer
D. Sy (f ) = 0 for f = (2n + 1) f= 1 kHz, n any integer
Answer : Option D
Explaination / Solution:



Workspace
Report
Q.8
A system with transfer function  has an output for the input signal  Then, the system parameter p is
A. √3
B. 2/√3
C. 1
D. √3/2
Answer : Option B
Explaination / Solution:

Transfer function is given as

Amplitude Response

Alternative :


Workspace
Report
Q.9
The signal flow graph of a system is shown below:

The state variable representation of the system can be
A.
B.
C.
D.
Answer : Option D
Explaination / Solution:



Workspace
Report
Q.10
The electric field component of a time harmonic plane EM wave traveling in a nonmagnetic lossless dielectric medium has an amplitude of 1 V/m. If the relative permittivity of the medium is 4, the magnitude of the time-average power density vector (in W/m2) is
A. 1/30π
B. 1/60π
C. 1/120π
D. 1/240π
Answer : Option C
Explaination / Solution:

Intrinsic impedance of EM wave

Time average power density


Workspace
Report